1. Field of the Invention
The present invention relates to a wavelength variable light source apparatus for use in optical measurement technical field or the like.
2. Description of the Related Art
As shown in FIG. 7, a wavelength variable light source apparatus 300 comprises a plurality of light source slot sections 301 and a main control section 302 (only one light source slot section is illustrated in FIG. 7). The light source slot sections 301 generate laser lights which have wavelength variable ranges different from one another, respectively. A selected one of the light source slot sections 301 may be inserted in one of plug sections 302a which are installed in the main control section 302, according to intended use.
The light source slot section 301 inserted in one of the plug sections 302a is connected to the main control section 302 through an electric connector 303 for use in control (communication) on optionally varying the wavelength and output level of the laser light which is outputted from the light source slot section 301. The electric connector 303 is installed on a back surface of the light source slot section 301. In addition, a light output connector 304 is installed on a front surface of the light source slot section 301.
By the way, the need for improvement of the light source wavelength precision is increasing year-by-year. In order to keep the wavelength of the laser light which is outputted from the light source slot section 301, with greater accuracy, a part of laser light is monitored by a wavelength detector such as a cymometer and compensation is carried out so as to make the wavelength of the laser light outputted from the light source slot section 301 be equal to a preset wavelength.
However, the light source slot section 301 is not optically connected to the main control section 302 and it is impossible to introduce the laser light outputted from the light source slot section 301, into the main control section 302, inasmuch as the light source slot section 301 is connected to the main control section 302 by only electric connector 303, in the above-mentioned conventional wavelength variable light source apparatus 300.
As a result, it is necessary to install an optical branch element or an optical fiber in the light output connector 304 which is installed on the front surface of the light source slot section 301 in order to branch off a part of laser light outputted from the light output connector 304, in case of monitoring the wavelength of the laser light outputted from the light source slot section 301, by the wavelength detector. In addition, a personal computer and special software need which are for use in compensating the wavelength of the laser light in accordance with wavelength information obtained by the wavelength detector. As a result, it is necessary to provide a wide working space.
Furthermore, the size of the light source slot section 301 increases inasmuch as each light source slot section 301 has the wavelength detector, in case where the wavelength detector is installed in each light source slot section 301. As a result, there is a problem in which the wavelength variable light source apparatus 300 is upsized. In addition, the number of the light source slot sections 301 decreases which is capable of being inserted into the main control section 302. The cost may increase with respect to the wavelength variable light source apparatus 300.